A truck overturned on the road where the incident occurred at about 150km from Juba.
According to multiple sources, 15 bodies were found late on Friday and 3 more bodies on Saturday. 5 people were injured and 5 others,who are all men, are missing.
Although the actual identities of the attackers remain unknown, survivors blamed Mundari tribesmen who inhabit the area. Others pointed fingers at Murle gunmen.
In 2009, clashes between Dinka Bor and the Mundari saw several dozen killed and thousands displaced, amid calls for calm from Tere-keka county and Jonglei state officials.